Part: expose geometry clone support to python

=============================================

>>> geometries = ActiveSketch.Geometry
>>> geo0 = geometries[0]
>>> geo0.Tag
'a2b6883e-64d6-4348-b567-8b5e0a4896a0'
>>> geo1 = geo0.clone()
>>> geo1.Tag
'a2b6883e-64d6-4348-b567-8b5e0a4896a0'
>>> geo1.Radius = 3
>>> geo0.Tag
'a2b6883e-64d6-4348-b567-8b5e0a4896a0'
>>> geo0.Radius
30.157883192724587
>>> geo1.Tag
'a2b6883e-64d6-4348-b567-8b5e0a4896a0'
>>> geo1.Radius
3.0

src/Mod/Part/App/GeometryPy.xml

@@ -1,13 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <GenerateModel xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="generateMetaModel_Module.xsd">
-  <PythonExport 
-      Father="PyObjectBase" 
-      Name="GeometryPy" 
-      Twin="Geometry" 
-      TwinPointer="Geometry" 
-      Include="Mod/Part/App/Geometry.h" 
-      Namespace="Part" 
-      FatherInclude="Base/PyObjectBase.h" 
+  <PythonExport
+      Father="PyObjectBase"
+      Name="GeometryPy"
+      Twin="Geometry"
+      TwinPointer="Geometry"
+      Include="Mod/Part/App/Geometry.h"
+      Namespace="Part"
+      FatherInclude="Base/PyObjectBase.h"
       FatherNamespace="Base"
       Constructor="true"
       Delete="true">
@@ -48,6 +48,11 @@ It describes the common behavior of these objects when:
         <UserDocu>Create a copy of this geometry</UserDocu>
       </Documentation>
     </Methode>
+    <Methode Name="clone" Const="true">
+        <Documentation>
+            <UserDocu>Create a clone of this geometry with the same Tag</UserDocu>
+        </Documentation>
+    </Methode>
     <Attribute Name="Construction" ReadOnly="false">
       <Documentation>
         <UserDocu>Defines this geometry as a construction one which

src/Mod/Part/App/GeometryPyImp.cpp

@@ -114,7 +114,7 @@ PyObject* GeometryPy::rotate(PyObject *args)
 
     rot.getValue(dir, angle);
     pnt = plm->getPosition();
-    
+
     gp_Ax1 ax1(gp_Pnt(pnt.x,pnt.y,pnt.z), gp_Dir(dir.x,dir.y,dir.z));
     getGeometryPtr()->handle()->Rotate(ax1, angle);
     Py_Return;
@@ -131,7 +131,7 @@ PyObject* GeometryPy::scale(PyObject *args)
         getGeometryPtr()->handle()->Scale(pnt, scale);
         Py_Return;
     }
-    
+
     PyErr_Clear();
     if (PyArg_ParseTuple(args, "O!d", &PyTuple_Type,&o, &scale)) {
         vec = Base::getVectorFromTuple<double>(o);
@@ -212,6 +212,33 @@ PyObject* GeometryPy::copy(PyObject *args)
     return cpy;
 }
 
+PyObject* GeometryPy::clone(PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, ""))
+        return NULL;
+
+    Part::Geometry* geom = this->getGeometryPtr();
+    PyTypeObject* type = this->GetType();
+    PyObject* cpy = 0;
+    // let the type object decide
+    if (type->tp_new)
+        cpy = type->tp_new(type, this, 0);
+    if (!cpy) {
+        PyErr_SetString(PyExc_TypeError, "failed to create clone of geometry");
+        return 0;
+    }
+
+    Part::GeometryPy* geompy = static_cast<Part::GeometryPy*>(cpy);
+    // the PyMake function must have created the corresponding instance of the 'Geometry' subclass
+    // so delete it now to avoid a memory leak
+    if (geompy->_pcTwinPointer) {
+        Part::Geometry* clone = static_cast<Part::Geometry*>(geompy->_pcTwinPointer);
+        delete clone;
+    }
+    geompy->_pcTwinPointer = geom->clone();
+    return cpy;
+}
+
 Py::Boolean GeometryPy::getConstruction(void) const
 {
     return Py::Boolean(getGeometryPtr()->Construction);
@@ -236,5 +263,5 @@ PyObject *GeometryPy::getCustomAttributes(const char* /*attr*/) const
 
 int GeometryPy::setCustomAttributes(const char* /*attr*/, PyObject* /*obj*/)
 {
-    return 0; 
+    return 0;
 }